Getting Started - Scripting in Java: Integrating with Groovy and JavaScript - page 12

The implementer of the ScriptEngine interface also provides an implementation of
the ScriptEngineFactory interface. A ScriptEngineFactory performs two tasks:
It creates instances of the script engine. •

• It provides information about the script engine such as engine

name, version, language, and so on.

The AbstractScriptEngine Class
The AbstractScriptEngine class is an abstract class. It provides a partial implementation
for the ScriptEngine interface. You will not use this class directly unless you are
implementing a script engine.

The ScriptEngineManager Class
The ScriptEngineManager class provides a discovery and instantiation mechanism
for script engines. It also maintains a mapping of key-value pairs as an instance of the
Bindings interface storing state that is shared by all script engines that it creates.

The Compilable Interface and the CompiledScript Class
The Compilable interface may optionally be implemented by a script engine that allows
compiling scripts for their repeated execution without recompilation.
The CompiledScript class is an abstract class. It is extended by the providers of a
script engine. It stores a script in a compiled form, which may be executed repeatedly
without recompilation. Note that using a ScriptEngine to execute a script repeatedly
causes the script to recompile every time, thus slowing down the performance.
A script engine is not required to support script compilation. It must implement the
Compilable interface if it supports script compilation.

The Invocable Interface
The Invocable interface may optionally be implemented by a script engine that may
allow invoking procedures, functions, and methods in scripts that have been compiled
previously.

The Bindings Interface and the SimpleBindings Class
An instance of a class that implements the Bindings interface is a mapping of
key-value pairs with a restriction that a key must be non-null, non-empty String . It
extends the java.util.Map interface. The SimpleBindings class is an implementation of
the Bindings interface.